a) Field of the Invention
The invention is directed to a spring winding device, particularly for spring winding machines, for producing, selectively, right-hand-wound or left-hand-wound helical springs from wire.
b) Description of the Related Art
A known spring coiling or spring winding device for spring winding machines (DE-PS 896 186) uses two winding tools which are arranged on slides and coupled together so as to be fixed with respect to movement by a level indirectly controlled by a cam disk. For this purpose, one slide is arranged on one side of the wire guide and the other slide is arranged on the other side of the wire guide, both slides being guided in a linear manner on a tool plate common to both. However, to switch this known device in order to generate springs with a different winding direction, it is necessary to replace the existing winding apparatus with a different winding apparatus because different spring winding devices must be used for springs with different winding directions.
In another known spring winding machine (DE-OS 23 10 174), two winding apparatuses are provided, each with a winding tool; the winding tool in the winding apparatus in question can be advanced linearly toward the exit location of the wire at the wire guide by means of a carriage or slide and a slide guide. In addition, each of the two winding apparatuses is arranged so as to be swivelable about a bearing axis which extends transverse to the axis of the wire guide and which is located at the end portion of the slide guide body remote of the wire guide. This known spring winding device allows every tool to be moved linearly and swiveled simultaneously, so that it can be used in the function of an inner winding tool as well as an outer winding tool. In this case, while it is possible to switch the winding direction without having to change the entire winding apparatus, it is impossible to produce shaped springs with this known device because no controlling means are provided for displacing the two winding tools relative to one another during the manufacturing of the spring.
A winding device which cannot be used for producing selectively right-hand helical springs or left-hand helical springs, but which is suitable for simultaneously generating noncylindrically shaped helical springs also is described in DE-GM 92 13 164. In this case, again, two winding apparatuses are used, each having a slide guide body in which a slide is displaceably arranged in such a way that a winding tool connected with the slide is guided so as to be moveable linearly relative to the point at which the wire exits the wire guide. Every slide guide body is swivelable at its end region remote of the wire guide around a swiveling axis directed vertical to the wire guide axis and parallel to a center plane extending through the wire guide axis, the two winding apparatuses being arranged on different sides of this center plane. A suitable cam drive is associated with each of the two winding apparatuses; in one winding apparatus, the cam drive pushes the slide back and forth in its guide, while in the other winding apparatus the cam drive swivels the slide guide body back and forth, and both movements are program-controlled relative to one another. However, switching the winding direction for the helical springs to be produced in this known winding device requires that a number of mechanical conversions be carried out, and it is necessary in particular to change the kinematic drive between the cam disk and winding apparatus and to change devices at the winding apparatuses themselves, which is still relatively time-consuming and complicated.
DE-OS 198 25 970 discloses a spring manufacturing arrangement using two tool units, each of which is fastened to a plate which is arranged so as to be movable in the wire guide direction to another plate which can, in turn, be moved vertical to the wire guide direction. Accordingly, each tool unit can be moved independently from the other in two coordinate directions extending perpendicular to one another, which allows the tip of the tool carried by the tool unit to move to any desired point. In this known device, it is possible to switch the spring winding direction without carrying out significant conversion arrangements essentially by switching the program control. However, this known spring winding device necessitates the use of four independently working servo motors and a plurality of individual elements which are arranged on and movable relative to one another, which represents a very great expenditure.
On this basis, it is the primary object of the invention to provide a spring winding device of the type mentioned above in which it is possible to switch the winding direction of the generated springs while substantially avoiding mechanical conversion operations and which nevertheless has a relatively simple construction.
According to the invention, this object is met by a spring winding device, in particular for spring winding machines, for producing, selectively, right-hand or left-hand helical springs from wire, with pull-in rollers for transporting the wire along a wire guide axis through a wire guide, with two winding apparatuses, each of which has a slide guide body in which a slide is displaceably arranged in such a way that a winding tool connected with the slide is guided so as to be moveable linearly relative to the point at which the wire exits the wire guide, wherein every slide guide body is swivelable at its end region remote of the wire guide around a swiveling axis directed vertical to the wire guide axis and parallel to a center plane extending through the wire guide axis, the two winding apparatuses being arranged on different sides of this center plane, wherein a drive for the movement of the slide and a cam drive controlled by a cam disk for swiveling the slide guide body about the swiveling axis are allocated to each winding apparatus, wherein a shared cam disk which is swivelable by a program-controlled motor and has two control portions and at least one rest portion is allocated to the cam drives of both winding apparatuses, wherein, further, each control portion is configured for introducing controlling movements in one of the two cam drives and every rest portion is configured for introducing no controlling movements in the cam drive, and, by rotation of the cam disk, one of the control portions for producing helical springs in one winding direction can be connected to the associated cam drive for control thereof, while the other cam drive contacts the rest portion or one of the rest portions, and wherein the controlled cam drive cooperates in a program-controlled manner with the drive unit for the movement of one of the slides, while the drive unit of the other slide is deactivated.
As a result of the mechanical movability of every tool holder in two movement directions which is provided in the spring winding device according to the invention, it is possible to produce non-round springs, time spent on adjustment is reduced, the reproducibility of adjustments is ensured, and the initial winding of the springs can be effected automatically for the first turn without manual effort. Through the use of a cam disk which is shared by both cam drives and which need only be rotated at a certain angle for connecting to one cam drive or the other, the conversion work for switching from right-handed winding to left-handed winding is minimized because it is necessary only to carry out the individual tool adjustments at the tool holder.
Further, the spring winding device according to the invention also provides greater rigidity of the overall arrangement through a more favorable flux of force and increased expenditure for assembly and maintenance for belt drives, as required in DE-GM 92 13 164, is done away with. It is also possible in the spring winding machine according to the invention to achieve a constant loading torque over the entire spring diameter range (with the identical wire diameter and with respect to the shaping forces) by using a specially calculated cam rule.
As a result of the cam disk which is used in the invention and shared by the two cam drives, it is also necessary to provide only three servo motors and accordingly to cover the overall basic principle of spring winding with three axes. In this way, all of the advantages are achieved merely through the use of a third motor without the need for another motor as is the case in the known spring winding device according to DE-OS 198 25 970. In addition, it is also possible to do away with the complicated arrangementxe2x80x94likewise employed in the prior artxe2x80x94of carrying tables for tool carrying devices which are arranged one above the other and which are movable relative to one another in different directions and the likewise rather complicated connection mechanism on one table which is required during the movement of a second table for the movement of two additional tables.
The individual motors for the drive unit for the common cam disk and for the two drive units for moving the slides are coupled with one another via an electronic program control which ensures that the motors which are used for the winding of springs in one winding direction exactly carry out the movements required for the production of the desired spring shape in a program-controlled manner.
In an advantageous arrangement of the invention, the cam drive of a winding apparatus cooperates in a program-controlled manner with the drive unit for the movement of the slide of the other winding apparatus, so that helical springs of one winding direction can be produced in the two-finger system. If springs are to be produced in the other winding direction, the cam drive of the other winding apparatus is correspondingly connected with the other drive for the linear movement of the slide.
When the spring winding device according to the invention is used for the shaping process in the case of forward feed of the wire in the one-finger system, the cam drive of a winding apparatus is preferably coupled in a program-controlled manner with the drive unit for the movement of the slide of the same winding apparatus, i.e., one winding apparatus is in use, while the other winding apparatus is deactivated.
If helical springs with a different winding direction are to be produced in the one-finger winding system, the cam drive of the other winding apparatus is preferably coupled in a program-controlled manner with the drive unit for the movement of the slide in this winding apparatus.
In the spring winding device according to the invention, any suitable type of drive can be used in principle as a drive unit for the movement of the slide in each winding apparatus. However, it is especially preferable when a cam disk which is rotatable by a program-controlled motor is provided as a drive unit for the movement of the slide in each winding apparatus, wherein the cam movement of the rotatable cam disk is transmitted in a positively controlled manner to the slide. This allows for the great advantage that the occurring weight forces and acceleration forces do not impair the accuracy of the traveling movements of the slide or tool holder due to the positive guidance.
In a particularly preferred manner, the axis of rotation of the cam disk common to the two cam drives is arranged in the spring winding device according to the invention in such a way that it intersects the projection of the wire guide axis at right angles and, in so doing, lies in the center plane. Accordingly, a mirror-symmetric arrangement of the cam drives on both sides of the center plane can be achieved, which leads to identical loading on the switched-on cam drives in both spring winding directions.
The winding apparatuses are also preferably arranged in a mirror-symmetric manner to the wire guide axis in a spring winding device according to the invention, wherein they are preferably constructed in a mirror-symmetric manner relative to one another.
In another preferred construction of the invention, a guide plate is arranged between the winding apparatuses symmetric to the wire guide axis in the projection thereof and at a distance from the wire exit point, which guide plate has a guide path on its two sides facing the winding apparatuses, the facing end of the slide guide body of the winding apparatus in question sliding on this guide path.
The invention will be described by way of example hereinafter with reference to the drawings.